Furigana – What's That?

Citing Wikipedia: "Furigana (振り仮名) is a Japanese reading aid, consisting of smaller kana printed next to a kanji or other character to indicate its pronunciation. In horizontal text, yokogaki (横書き), they are placed above the line of text, while in vertical text, tategaki (縦書き), they are placed to the right of the line of text. Furigana are also known as yomigana (読み仮名) or rubi (ルビ) in Japanese."